Boffins discovers STORR gene required for Morphinan biosynthesis in opium poppy

Last month, a study published in the journal Nature reported that scientists have successfully identified almost every single step of the process that uses genetically engineered yeast to convert the sugar into morphine. Those steps are enough only for preparing a compound known as reticuline, the precursor of opiates made from poppies.

This left the researchers just a step before they could theoretically develop yeast designed for churning out narcotics. According to a study published in the journal Science on Thursday, June 25, another team of researchers have succeeded in making that leap.

Unlike last month’s study, genetically engineered yeast doesn’t have much to do in this new study. This study is basically a joint effort of GlaxoSmithKline Australia and a research team at the University of York.

The team was studying poppies used for producing natural morphinans that are later turned into morphine and codeine. The study introduced them to a new gene called STORR. This gene allows some poppy plants to make opiates.

The scientists found that the poppy plants that don’t have the STORR gene kept on amassing reticuline, which indicated a block in the process of opiate production. The presence of STORR, on the other hand, allowed the plants to continue with the production procedure.

University of York’s Ian Graham, the lead author of the study, said that this finding is quite interesting as STORR is the much anticipated missing link in the process of morphine production. The gene, according to Graham, symbolizes the final uncharacterized step of morphine production.

However, Graham’s team is showing more interest in producing poppies that GlaxoSmithKline already grows in huge quantity. Graham informed that a piece of land, which is as big as a football pitch, is large enough for producing around 50-kg morphine. According to him, it’s an extremely inexpensive way of growing such an important pharmaceutical ingredient.

Looking at these developments it can be said that genetically engineered yeasts, which are most likely capable of producing very small quantities of morphine, will not be able to compete with the STORR-based production procedure anytime soon.

So, scientists will now concentrate on gathering more information about STORR and its working procedure. They will now work to find out how the gene can be harnessed for increasing the efficacy of farm-grown production.

Describing STORR as an interesting gene, Graham said that it’s a fusion of two different genes. According to him, STORR contains two independent genes that have come together to bring two different enzymes together. Graham and his team are now interested to know how the gene evolved.